CRF receptor antagonists and methods relating thereto

ABSTRACT

CRF receptor antagonists are disclosed which have utility in the treatment of a variety of disorders, including the treatment of disorders manifesting hypersecretion of CRF in a warm-blooded animals, such as stroke. The CRF receptor antagonists of this invention have the following structure:  
                 
 
     including stereoisomers, prodrugs and pharmaceutically acceptable salts thereof, wherein R 1 , R 2 , R 5 , R 6 , X and Y are as defined herein. Compositions containing a CRF receptor antagonist in combination with a pharmaceutically acceptable carrier are also disclosed, as well as methods for use of the same

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of U.S. patent applicationSer. No. 10/036,752 filed Dec. 21, 2001, now allowed, and claims thebenefit of U.S. Provisional Patent Application No. 60/258,685 filed Dec.28, 2000, where these applications are incorporated herein by referencein their entireties.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to CRF receptor antagonists, andto methods of treating disorders by administration of such antagoniststo a warm-blooded animal in need thereof.

[0004] 2. Description of the Related Art

[0005] The first corticotropin-releasing factor (CRF) was isolated fromovine hypothalmi and identified as a 41-amino acid peptide (Vale et al.,Science 213:1394-1397, 1981). Subsequently, sequences of human and ratCRF were isolated and determined to be identical, but different fromovine CRF in 7 of the 41 amino acid residues (Rivier et al., Proc. Natl.Acad. Sci. USA 80:4851, 1983; Shibahara et al., EMBO J. 2:775, 1983).

[0006] CRF has been found to produce profound alterations in endocrine,nervous and immune system function. CRF is believed to be the majorphysiological regulator of the basal and stress-release ofadrenocorticotropic hormone (“ACTH”), β-endorphin, and otherpro-opiomelanocortin (“POMC”)-derived peptides from the anteriorpituitary (Vale et al., Science 213:1394-1397, 1981). Briefly, CRF isbelieved to initiate its biological effects by binding to a plasmamembrane receptor which has been found to be distributed throughout thebrain (DeSouza et al., Science 224:1449-1451, 1984), pituitary (DeSouzaet al., Methods Enzymol. 124:560, 1986; Wynn et al., Biochem. Biophys.Res. Comm. 110:602-608, 1983), adrenals (Udelsman et al., Nature319:147-150, 1986) and spleen (Webster, E. L., and E. B. DeSouza,Endocrinology 122:609-617, 1988). The CRF receptor is coupled to aGTP-binding protein (Perrin et al., Endocrinology 118:1171-1179, 1986)which mediates CRF-stimulated increase in intracellular production ofcAMP (Bilezikjian, L. M., and W. W. Vale, Endocrinology 113:657-662,1983). The receptor for CRF has now been cloned from rat (Perrin et al.,Endo 133(6):3058-3061, 1993), and human brain (Chen et al., PNAS90(19):8967-8971, 1993; Vita et al., FEBS 335(1):1-5, 1993). Thisreceptor is a 415 amino acid protein comprising seven membrane spanningdomains. A comparison of identity between rat and human sequences showsa high degree of homology (97%) at the amino acid level.

[0007] In addition to its role in stimulating the production of ACTH andPOMC, CRF is also believed to coordinate many of the endocrine,autonomic, and behavioral responses to stress, and may be involved inthe pathophysiology of affective disorders. Moreover, CRF is believed tobe a key intermediary in communication between the immune, centralnervous, endocrine and cardiovascular systems (Crofford et al., J. Clin.Invest. 90:2555-2564, 1992; Sapolsky et al., Science 238:522-524, 1987;Tilders et al., Regul. Peptides 5:77-84, 1982). Overall, CRF appears tobe one of the pivotal central nervous system neurotransmitters and playsa crucial role in integrating the body's overall response to stress.

[0008] Administration of CRF directly to the brain elicits behavioral,physiological, and endocrine responses identical to those observed foran animal exposed to a stressful environment. For example,intracerebroventricular injection of CRF results in behavioralactivation (Sutton et al., Nature 297:331, 1982), persistent activationof the electroencephalogram (Ehlers et al., Brain Res. 278:332, 1983),stimulation of the sympathoadrenomedullary pathway (Brown et al.,Endocrinology 110:928, 1982), an increase of heart rate and bloodpressure (Fisher et al., Endocrinology 110:2222, 1982), an increase inoxygen consumption (Brown et al., Life Sciences 30:207, 1982),alteration of gastrointestinal activity (Williams et al., Am. J.Physiol. 253:G582, 1987), suppression of food consumption (Levine etal., Neuropharmacology 22:337, 1983), modification of sexual behavior(Sirinathsinghji et al., Nature 305:232, 1983), and immune functioncompromise (Irwin et al., Am. J. Physiol. 255:R744, 1988). Furthermore,clinical data suggests that CRF may be hypersecreted in the brain indepression, anxiety-related disorders, and anorexia nervosa. (DeSouza,Ann. Reports in Med. Chem. 25:215-223, 1990). Accordingly, clinical datasuggests that CRF receptor antagonists may represent novelantidepressant and/or anxiolytic drugs that may be useful in thetreatment of the neuropsychiatric disorders manifesting hypersecretionof CRF.

[0009] The first CRF receptor antagonists were peptides (see, e.g.,Rivier et al., U.S. Pat. No. 4,605,642; Rivier et al., Science 224:889,1984). While these peptides established that CRF receptor antagonistscan attenuate the pharmacological responses to CRF, peptide CRF receptorantagonists suffer from the usual drawbacks of peptide therapeuticsincluding lack of stability and limited oral activity. More recently,small molecule CRF receptor antagonists have been reported. For example,substituted 4-thio-5-oxo-3-pyrazoline derivatives (Abreu et al., U.S.Pat. No. 5,063,245) and substituted 2-aminothiazole derivatives(Courtemanche et al., Australian Patent No. AU-A-41399/93) have beenreported as CRF receptor antagonists. These particular derivatives werefound to be effective in inhibiting the binding of CRF to its receptorin the 1-10 μM range and 0.1-10 μM range, respectively.

[0010] Due to the physiological significance of CRF, the development ofbiologically-active small molecules having significant CRF receptorbinding activity and which are capable of antagonizing the CRF receptorremains a desirable goal. Such CRF receptor antagonists would be usefulin the treatment of endocrine, psychiatric and neurologic conditions orillnesses, including stress-related disorders in general.

[0011] While significant strides have been made toward achieving CRFregulation through administration of CRF receptor antagonists, thereremains a need in the art for effective small molecule CRF receptorantagonists. There is also a need for pharmaceutical compositionscontaining such CRF receptor antagonists, as well as methods relating tothe use thereof to treat, for example, stress-related disorders. Thepresent invention fulfills these needs, and provides other relatedadvantages.

BRIEF SUMMARY OF THE INVENTION

[0012] In brief, this invention is generally directed to CRF receptorantagonists, and more specifically to CRF receptor antagonists havingthe following general structure (I):

[0013] including stereoisomers, prodrugs and pharmaceutically acceptablesalts thereof, wherein R₁, R₂, R₅, R₆, X and Y are as defined below.

[0014] The CRF receptor antagonists of this invention have utility overa wide range of therapeutic applications, and may be used to treat avariety of disorders or illnesses, including stress-related disorders.Such methods include administering an effective amount of a CRF receptorantagonist of this invention, preferably in the form of a pharmaceuticalcomposition, to an animal in need thereof. Accordingly, in anotherembodiment, pharmaceutical compositions are disclosed containing one ormore CRF receptor antagonists of this invention in combination with apharmaceutically acceptable carrier and/or diluent.

[0015] These and other aspects of the invention will be apparent uponreference to the following detailed description. To this end, variousreferences are set forth herein which describe in more detail certainprocedures, compounds and/or compositions, and are hereby incorporatedby reference in their entirety.

DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention is directed generally to compounds usefulas corticotropin-releasing factor (CRF) receptor antagonists having thefollowing structure (I):

[0017] including stereoisomers, prodrugs and pharmaceutically acceptablesalts thereof,

[0018] wherein:

[0019] X is nitrogen or CR₃;

[0020] Y is nitrogen or CR₄;

[0021] R₁ is alkyl, substituted alkyl, —NR₇R₈, aryl, substituted aryl,heteroaryl or substituted heteroaryl;

[0022] R₂ is hydrogen, alkyl, alkoxy, thioalkyl or haloalkyl;

[0023] R₃ is hydrogen, alkyl, halo or haloalkyl;

[0024] R₄ is hydrogen, halogen, —NR₇R₈, alkyl, alkoxy, thioalkyl orhaloalkyl;

[0025] R₅ is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl,heteroaryl or substituted heteroaryl;

[0026] R₆ is hydrogen, alkyl, substituted alkyl, —NR₇R₈, —OR₉, —SR₉,aryl, substituted aryl, heteroaryl or substituted heteroaryl;

[0027] R₇ and R₈ are the same or different and independently hydrogen,alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl orsubstituted heteroaryl; and

[0028] R₉ is alkyl, substituted alkyl, aryl, substituted aryl,heteroaryl or substituted heteroaryl.

[0029] As used herein, the above terms have the following meaning:

[0030] “Alkyl” means a straight chain or branched, noncyclic or cyclic,unsaturated or saturated aliphatic hydrocarbon containing from 1 to 10carbon atoms, while the term “lower alkyl” has the same meaning as alkylbut contains from 1 to 6 carbon atoms. Representative saturated straightchain alkyls include methyl, ethyl, n-propyl, n-butyl, n-pentyl,n-hexyl, and the like; while saturated branched alkyls includeisopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, and the like.Representative saturated cyclic alkyls include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, —CH₂cyclopropyl, —CH₂cyclobutyl,—CH₂cyclopentyl, —CH₂cyclohexyl, and the like; while unsaturated cyclicalkyls include cyclopentenyl and cyclohexenyl, and the like. Cyclicalkyls, also referred to as “homocyclic rings,” and include di- andpoly-homocyclic rings such as decalin and adamantyl. Unsaturated alkylscontain at least one double or triple bond between adjacent carbon atoms(referred to as an “alkenyl” or “alkynyl”, respectively). Representativestraight chain and branched alkenyls include ethylenyl, propylenyl,1-butenyl, 2-butenyl, isobutylenyl, 1-pentenyl, 2-pentenyl,3-methyl-1-butenyl, 2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, and thelike; while representative straight chain and branched alkynyls includeacetylenyl, propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl,3-methyl-1butynyl, and the like.

[0031] “Aryl” means an aromatic carbocyclic moiety such as phenyl ornaphthyl.

[0032] “Arylalkyl” means an alkyl having at least one alkyl hydrogenatoms replaced with an aryl moiety, such as benzyl, —CH₂-(1 or2-naphthyl), —(CH₂)₂phenyl, —(CH₂)₃phenyl, —CH(phenyl)₂, and the like.

[0033] “Heteroaryl” means an aromatic heterocycle ring of 5- to 10members and having at least one heteroatom selected from nitrogen,oxygen and sulfur, and containing at least 1 carbon atom, including bothmono- and bicyclic ring systems. Representative heteroaryls include (butare not limited to) furyl, benzofuranyl, thiophenyl, benzothiophenyl,pyrrolyl, indolyl, isoindolyl, azaindolyl, pyridyl, quinolinyl,isoquinolinyl, oxazolyl, isooxazolyl, benzoxazolyl, pyrazolyl,imidazolyl, benzimidazolyl, thiazolyl, benzothiazolyl, isothiazolyl,pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, cinnolinyl,phthalazinyl, oxadiazolyl, thiadiazolyl, benzisoxazolyl, triazolyl,tetrazolyl, indazolyl, and quinazolinyl.

[0034] “Heteroarylalkyl” means an alkyl having at least one alkylhydrogen atom replaced with a heteroaryl moiety, such as —CH₂pyridinyl,—CH₂pyrimidinyl, and the like.

[0035] “Heterocycle” (also referred to herein as a “heterocycle ring”)means a 5- to 7-membered monocyclic, or 7- to 14-membered polycyclic,heterocycle ring which is either saturated, unsaturated or aromatic, andwhich contains from 1 to 4 heteroatoms independently selected fromnitrogen, oxygen and sulfur, and wherein the nitrogen and sulfurheteroatoms may be optionally oxidized, and the nitrogen heteroatom maybe optionally quaternized, including bicyclic rings in which any of theabove heterocycles are fused to a benzene ring as well as tricyclic (andhigher) heterocyclic rings. The heterocycle may be attached via anyheteroatom or carbon atom. Heterocycles include heteroaryls as definedabove. Thus, in addition to the aromatic heteroaryls listed above,heterocycles also include (but are not limited to) morpholinyl,pyrrolidinonyl, pyrrolidinyl, piperidinyl, hydantoinyl, valerolactamyl,oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl,tetrahydropyridinyl, tetrahydroprimidinyl, tetrahydrothiophenyl,tetrahydrothiopyranyl, tetrahydropyrimidinyl, tetrahydrothiophenyl,tetrahydrothiopyranyl, and the like.

[0036] “Heterocyclealkyl” means an alkyl having at least one alkylhydrogen atom replaced with a heterocycle, such as —CH₂morpholinyl, andthe like.

[0037] The term “substituted” as used herein means any of the abovegroups (e.g. alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl,heterocycle and heterocyclealkyl) wherein at least one hydrogen atom isreplaced with a substituent. In the case of an oxo substituent (“═O”)two hydrogen atoms are replaced. When substituted, “substituents” withinthe context of this invention include halogen, hydroxy, oxo, cyano,nitro, amino, alkylamino, dialkylamino, alkyl, alkoxy, alkylthio,haloalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl,heteroaryl, substituted heteroaryl, heteroarylalkyl, substitutedheteroarylalkyl, heterocycle, substituted heterocycle, heterocyclealkyl,substituted heterocyclealkyl, —NR_(a)R_(b), —NR_(a)C(═O)R_(b),—NR_(a)C(═O)NR_(a)R_(b), —NR_(a)C(═O)OR_(b) —NR_(a)SO₂R_(b), —OR_(a),—C(═O)R_(a) —C(═O)OR_(a), —C(═O)NR_(a)R_(b), —OC(═O)NR_(a)R_(b),—SR_(a), —SOR_(a), —S(═O)₂R_(a), —OS(═O)₂R_(a), —S(═O)₂OR_(a), whereinR_(a) and R_(b) are the same or different and independently hydrogen,alkyl, substituted alkyl (such as haloalkyl), aryl, substituted aryl,arylalkyl, substituted arylalkyl, heteroaryl, substituted heteroaryl,heteroarylalkyl, substituted heteroarylalkyl, heterocycle, substitutedheterocycle, heterocyclealkyl or substituted heterocyclealkyl.

[0038] “Halogen” means fluoro, chloro, bromo and iodo.

[0039] “Haloalkyl” means an alkyl having at least one hydrogen atomreplaced with halogen, such as trifluoromethyl and the like.

[0040] “Alkoxy” means an alkyl moiety attached through an oxygen bridge(i.e., —O-alkyl) such as methoxy, ethoxy, and the like.

[0041] “Thioalkyl” means an alkyl moiety attached through a sulfurbridge (i.e., —S-alkyl) such as methylthio, ethylthio, and the like.

[0042] “Alkylamino” and “dialkylamino” mean an amino substituted withone alkyl or with two alkyls, respectively, such as methylamino,ethylamino, dimethylamino, diethylamino, and the like.

[0043] “Hydroxyalkyl” means an alkyl substituted with at least onehydroxyl group.

[0044] “Alkylcarbonylalkyl” represents an alkyl substituted with a—C(═O)alkyl group.

[0045] “Alkylcarbonyloxyalkyl” represents an alkyl substituted with a—C(═O)Oalkyl group or a —OC(═O)alkyl group.

[0046] “Alkyloxyalkyl” represents an alkyl substituted with a —O-alkylgroup.

[0047] “Alkylthioalkyl” represents an alkyl substituted with a —S-alkylgroup.

[0048] Depending upon the Y and X substituents, representative compoundsof this invention have one of the following structures (II), (III), (IV)or (V):

[0049] In more specific embodiments of this invention, representative R₁groups of this invention include (but are not limited to)2,4-dichlorophenyl, 2,4-dimethyl-phenyl, 2-chloro-4-methylphenyl,2-methyl-4-chlorophenyl, 2,4,6-trimethylphenyl,2-chloro-4-methoxyphenyl, 2-methyl-4-methoxyphenyl, 2,4-dimethoxyphenyl,2-trifluoromethyl-4-chlorophenyl, 3-methoxy-4-chlorophenyl,2,5-dimethoxy-4-chlorophenyl, 2-methoxy-4-trichloromethylphenyl,2-methoxy-4-isopropylphenyl, 2-methoxy-4-trifluoromethylphenyl,2-methoxy-4-isopropylphenyl 2-methoxy-4-methylphenyl,4-methyl-6-dimethylaminopyridin-3-yl,4-dimethylamino-6-methyl-pyridin-3-yl, 6-dimethylaminopyridin-3-yl and4-dimethylamino-pyridin-3-yl.

[0050] Similarly, representative R₂ groups include hydrogen and alkylsuch as methyl and ethyl, while representative R₃ groups includehydrogen, halogen such as chlorine, fluorine and bromine, alkyl such asmethyl and ethyl, and haloalkyl such as trifluoromethyl.

[0051] Representative R₄ groups include hydrogen, halogen such aschlorine, fluorine and bromine, alkyl such as methyl and ethyl,haloalkyl such as trifluoromethyl, substituted amino such as methyl ordimethylamino, thioalkyl such as thiomethyl and alkoxy such as ethoxy.Representative R₅ groups include hydrogen, alkyl such as methyl, ethyl,propyl, butyl, pentyl, heptyl, octyl, nonyl including branched andstraight chains, saturated and unsaturated, substituted alkyl such asbenzyl and phenethyl, aryl such as phenyl or naphthyl, and heterocyclesuch as pyridyl or furyl. Representative R₆ groups include hydrogen andalkyl such as methyl or ethyl. Representative R₇ and R₈ groups are asdisclosed above for R₅.

[0052] The compounds of the present invention may generally be utilizedas the free base. Alternatively, the compounds of this invention may beused in the form of acid addition salts. Acid addition salts of the freebase amino compounds of the present invention may be prepared by methodswell known in the art, and may be formed from organic and inorganicacids. Suitable organic acids include maleic, fumaric, benzoic,ascorbic, succinic, methanesulfonic, acetic, oxalic, propionic,tartaric, salicylic, citric, gluconic, lactic, mandelic, cinnamic,aspartic, stearic, palmitic, glycolic, glutamic, and benzenesulfonicacids. Suitable inorganic acids include hydrochloric, hydrobromic,sulfuric, phosphoric, and nitric acids. Thus, the term “pharmaceuticallyacceptable salt” of structure (I) is intended to encompass any and allacceptable salt forms.

[0053] The compounds of structure (I) may be made according to theorganic synthesis techniques known to those skilled in this field, aswell as by the representative methods set forth in the Examples.

[0054] The effectiveness of a compound as a CRF receptor antagonist maybe determined by various assay methods. Suitable CRF antagonists of thisinvention are capable of inhibiting the specific binding of CRF to itsreceptor and antagonizing activities associated with CRF. A compound ofstructure (I) may be assessed for activity as a CRF antagonist by one ormore generally accepted assays for this purpose, including (but notlimited to) the assays disclosed by DeSouza et al. (J. Neuroscience7:88, 1987) and Battaglia et al. (Synapse 1:572, 1987). As mentionedabove, suitable CRF antagonists include compounds which demonstrate CRFreceptor affinity. CRF receptor affinity may be determined by bindingstudies that measure the ability of a compound to inhibit the binding ofa radiolabeled CRF (e.g., [¹²⁵I]tyrosine-CRF) to its receptor (e.g.,receptors prepared from rat cerebral cortex membranes). The radioligandbinding assay described by DeSouza et al. (supra, 1987) provides anassay for determining a compound's affinity for the CRF receptor. Suchactivity is typically calculated from the IC₅₀ as the concentration of acompound necessary to displace 50% of the radiolabeled ligand from thereceptor, and is reported as a “K_(i)” value calculated by the followingequation: $K_{i} = \frac{{IC}_{50}}{1 + {L/K_{D}}}$

[0055] where L=radioligand and K_(D)=affinity of radioligand forreceptor (Cheng and Prusoff, Biochem. Pharmacol 22:3099, 1973).

[0056] In addition to inhibiting CRF receptor binding, a compound's CRFreceptor antagonist activity may be established by the ability of thecompound to antagonize an activity associated with CRF. For example, CRFis known to stimulate various biochemical processes, including adenylatecyclase activity. Therefore, compounds may be evaluated as CRFantagonists by their ability to antagonize CRF-stimulated adenylatecyclase activity by, for example, measuring cAMP levels. TheCRF-stimulated adenylate cyclase activity assay described by Battagliaet al. (supra, 1987) provides an assay for determining a compound'sability to antagonize CRF activity. Accordingly, CRF receptor antagonistactivity may be determined by assay techniques which generally includean initial binding assay (such as disclosed by DeSouza (supra, 1987))followed by a cAMP screening protocol (such as disclosed by Battaglia(supra, 1987)).

[0057] With reference to CRF receptor binding affinities, CRF receptorantagonists of this invention have a K_(i) of less than 10 μM. In apreferred embodiment of this invention, a CRF receptor antagonist has aK_(i) of less than 1 μM, more preferably less than 0.25 μM (i.e., 250nM), and most preferably less than 100 nM. To this end, compounds 7-9,7-10 and 8-3 (see Examples 7 and 8) have K_(i) values of less than 100nM. As set forth in greater detail below, the K_(i) values ofrepresentative compounds of this invention were assayed by the methodsset forth in Example 9. The CRF receptor antagonists of the presentinvention demonstrate activity at the CRF receptor site, and may be usedas therapeutic agents for the treatment of a wide range of disorders orillnesses including endocrine, psychiatric, and neurologic disorders orillnesses. More specifically, the CRF receptor antagonists of thepresent invention may be useful in treating physiological conditions ordisorders arising from the hypersecretion of CRF. Because CRF isbelieved to be a pivotal neurotransmitter that activates and coordinatesthe endocrine, behavioral and automatic responses to stress, the CRFreceptor antagonists of the present invention can be used to treatneuropsychiatric disorders. Neuropsychiatric disorders which may betreatable by the CRF receptor antagonists of this invention includeaffective disorders such as depression; anxiety-related disorders suchas generalized anxiety disorder, panic disorder, obsessive-compulsivedisorder, abnormal aggression, cardiovascular abnormalities such asunstable angina and reactive hypertension; and feeding disorders such asanorexia nervosa, bulimia, and irritable bowel syndrome. CRF antagonistsmay also be useful in treating stress-induced immune suppressionassociated with various disease states, as well as stroke. Other uses ofthe CRF antagonists of this invention include treatment of inflammatoryconditions (such as rheumatoid arthritis, uveitis, asthma, inflammatorybowel disease and G.I. motility), Cushing's disease, infantile spasms,epilepsy and other seizures in both infants and adults, and varioussubstance abuse and withdrawal (including alcoholism).

[0058] In another embodiment of the invention, pharmaceuticalcompositions containing one or more CRF receptor antagonists aredisclosed. For the purposes of administration, the compounds of thepresent invention may be formulated as pharmaceutical compositions.Pharmaceutical compositions of the present invention comprise a CRFreceptor antagonist of the present invention (i.e., a compound ofstructure (I)) and a pharmaceutically acceptable carrier and/or diluent.The CRF receptor antagonist is present in the composition in an amountwhich is effective to treat a particular disorder—that is, in an amountsufficient to achieve CRF receptor antagonist activity, and preferablywith acceptable toxicity to the patient. Preferably, the pharmaceuticalcompositions of the present invention may include a CRF receptorantagonist in an amount from 0.1 mg to 250 mg per dosage depending uponthe route of administration, and more preferably from 1 mg to 60 mg.Appropriate concentrations and dosages can be readily determined by oneskilled in the art.

[0059] Pharmaceutically acceptable carrier and/or diluents are familiarto those skilled in the art. For compositions formulated as liquidsolutions, acceptable carriers and/or diluents include saline andsterile water, and may optionally include antioxidants, buffers,bacteriostats and other common additives. The compositions can also beformulated as pills, capsules, granules, or tablets which contain, inaddition to a CRF receptor antagonist, diluents, dispersing and surfaceactive agents, binders, and lubricants. One skilled in this art mayfurther formulate the CRF receptor antagonist in an appropriate manner,and in accordance with accepted practices, such as those disclosed inRemington's Pharmaceutical Sciences, Gennaro, Ed., Mack Publishing Co.,Easton, Pa. 1990.

[0060] In addition, prodrugs are also included within the context ofthis invention. Prodrugs are any covalently bonded carriers that releasea compound of structure (I) in vivo when such prodrug is administered toa patient. Prodrugs are generally prepared by modifying functionalgroups in a way such that the modification is cleaved, either by routinemanipulation or in vivo, yielding the parent compound.

[0061] With regard to stereoisomers, the compounds of structure (I) mayhave chiral centers and may occur as racemates, racemic mixtures and asindividual enantiomers or diastereomers. All such isomeric forms areincluded within the present invention, including mixtures thereof.Furthermore, some of the crystalline forms of the compounds of structure(I) may exist as polymorphs, which are included in the presentinvention. In addition, some of the compounds of structure (I) may alsoform solvates with water or other organic solvents. Such solvates aresimilarly included within the scope of this invention.

[0062] In another embodiment, the present invention provides a methodfor treating a variety of disorders or illnesses, including endocrine,psychiatric and neurologic disorders or illnesses. Such methods includeadministering of a compound of the present invention to a warm-bloodedanimal in an amount sufficient to treat the disorder or illness. Suchmethods include systemic administration of a CRF receptor antagonist ofthis invention, preferably in the form of a pharmaceutical composition.As used herein, systemic administration includes oral and parenteralmethods of administration. For oral administration, suitablepharmaceutical compositions of CRF receptor antagonists include powders,granules, pills, tablets, and capsules as well as liquids, syrups,suspensions, and emulsions. These compositions may also includeflavorants, preservatives, suspending, thickening and emulsifyingagents, and other pharmaceutically acceptable additives. For parentaladministration, the compounds of the present invention can be preparedin aqueous injection solutions which may contain, in addition to the CRFreceptor antagonist, buffers, antioxidants, bacteriostats, and otheradditives commonly employed in such solutions.

[0063] In another embodiment, compounds of this invention may be used asPositron Emission Tomography (PET) ligands, Single Photon EmissionComputed Tomography (SPECT) ligands, or other diagnosticradiopharmaceutical agents. Incorporation of an appropriate isotope(such as ¹¹C or ¹⁸F for PET or ¹²⁵I in the case of SPECT) providesagents useful for the diagnosis or therapeutic management of a patient.In addition, use of a compound of the present invention may provide aphysiological, functional, or biological assessment of a patient orprovide disease or pathology detection and assessment.

[0064] As mentioned above, administration of a compound of the presentinvention can be used to treat a wide variety of disorders or illnesses.In particular, the compounds of the present invention may beadministered to a warm-blooded animal for the treatment of depression,anxiety disorder, panic disorder, obsessive-compulsive disorder,abnormal aggression, unstable angina, reactive hypertension, anorexianervosa, bulimia, irritable bowel syndrome, stress-induced immunesuppression, stroke, inflammation, Cushing's disease, infantile spasms,epilepsy, and substance abuse or withdrawal.

[0065] The following examples are provided for purposes of illustration,not limitation.

EXAMPLES

[0066] The CRF receptor antagonists of this invention may be prepared bythe methods disclosed in Examples 1 through 8. Example 9 presents amethod for determining the receptor binding activity (K_(i)), whileExample 10 discloses an assay for screening compounds of this inventionfor CRF-stimulated adenylate cyclase activity.

Example 1 Synthesis of Intermediate for Structure (II)

[0067]

[0068] Compound 1-1

[0069] The 4-nitro pyrazole is added to a suspension of palladium oncarbon 10% in ethanol (100 mL). The mixture is shaken for 3 hours underhydrogen gas (40 psi) at room temperature. Completion of the reaction ischecked by TLC (ethylacetate/hexane 1/1, nitropyrazole Rf 0.6, UVactive, amino-pyrazole Rf 0.1, UV active). The catalyst is removed byfiltration through celite and the solvents are evaporated. The product1-1, a burgundy solid, is used in the following step withoutpurification

[0070] Compound 1-2

[0071] A solution of 4-amino pyrazole 1-1 (0.4 mol, 1 eq) is stirred ina mixture of acetonitrile/dioxane. HCl gas is bubbled through thereaction mixture. When all the starting material is consumed, thereaction mixture is basified with NH₄OH and extracted with ethylacetate. The organic layers are combined and are washed three times withwater and brine. The organic phase is dried (MgSO₄) and concentrated invacuo. Purification via flash chromatography gives the desired product1-2.

[0072] Compound 1-3

[0073] Compound 1-2 is heated at 90° C. in a mixture ofPOCl₃/acetonitrile (90 mL/100 mL) for 5 hours. After cooling to roomtemperature, the reaction mixture is poured onto ice and is neutralizedwith a 6N NaOH solution. The product is purified by liquidchromatography. The chloro compound is dissolved in 800 mL of a mixtureof water/methanol (1/1) cooled in an ice-bath. A bromine solution (12 mLof bromine in 100 mL H₂O/MeOH 1/1) is added dropwise to the cooledmixture. After 10 minutes, the solution is clearer and the LC/MS showsno chloro compound. The reaction mixture is concentrated, extracted withethyl acetate (3×10 mL). The organic phases are combined, washed withwater (2×50 mL), a brine solution (1×50 mL) and dried with sodiumthiosulfate. The product is purified by liquid chromatography (ethylacetate/hexane 1/1 Rf 0.7) to give 1-3.

Example 2 Synthesis of Intermediate for Structure (III)

[0074]

[0075] Compound 2-1

[0076] To a 5 L, 3-neck round-bottom flask equipped with a mechanicalstirrer was charged 1500 mL of concentrated sulfuric acid and thesolution cooled with an icebath. To this was charged 200 g (2940 mmol)of pyrazole keeping the reaction temperature <40° C. To the mixture wasslowly added 200 mL (3200 mmol, 1.1 eq.) of 70% nitric acid keeping thereaction temperature between 50-60° C. The mixture was warmed to 55° C.and stirred for 3 hr. The mixture was cooled and poured over 3000 g ofice. The mixture was neutralized with 9300 mL of 6N sodium hydroxide.The precipitate was filtered and the filtrate extracted 3× with ethylacetate. The combined organic phases were washed with brine and driedover magnesium sulfate. The solvent was removed in vacuo and the solidrecrystallized from ethanol affording 111 g of 2-1 (33% yield). M.W.113.08; TLC 1:1 ethyl acetate/hexane R_(f)=0.6; GCt_(R)=4.69 min.; MS[M+1]⁺ 114; ¹H NMR (CDCl₃) (Pyrazole GC_(TR)=3.1-3.5 min).

[0077] Compound 2-2

[0078] To a 500-mL, Parr bottle under nitrogen atmosphere was charged23.6 g (210 mmol) of 4-nitropyrazole 2-1, 100 mL of ethanol and 2.1 g of10% palladium on Carbon. The mixture was shaken under a hydrogenatmosphere at 40 psi at ambient temperature for 3 hr. The mixture wasflushed with nitrogen, filtered over a pad of celite, and the filtercake washed with ethanol. The solvent was removed in vacuo affording16.6 g (95% yield) of 2-2 as a burgundy oil. M.W. 83.09; TLC 1:1 ethylacetate/hexane R_(f)=0.1; GCt_(R)=3.66 min.; MS [M+1]⁺ 84; ¹H NMR(CDCl₃).

[0079] Compound 2-3

[0080] To a 2 L round bottom flask equipped with a Dean-Stark trap andcondenser was charged 150 g (1800 mmol) of 4-amino pyrazole 2-2, 800 mLof toluene, 200 mL (1620 mmol, 0.90 eq.) of ethylacetoacetate(R₂C(O)CHR₃CO₂Et where R₂ is methyl and R₃ is H) and 16 g (84 mmol, 0.05eq.) of p-toluene sulfonic acid monohydrate. The mixture was refluxeduntil TLC indicated only a residual amount of starting material. Thesolvent was removed in vacuo and the purple solid dissolved in ethylacetate (approximately 2 L required). The crude solution was filteredthrough a plug of silica gel and the silica gel washed with ethylacetate until no further product eluted. The solvent was removed invacuo affording 2-3 as an off-white solid. M.W. 195.22; TLC 1:1 ethylacetate/hexane Rf=0.3; MS [M+1]¹ 196; ¹H NMR (CDCl₃).

[0081] Compound 2-4

[0082] To a 250 mL, round bottom flask was charged 70 mL of diphenylether and 30 mL of dioxane. The mixture was heated using an oil bath at200° C. To the hot solution was carefully charged 30 g (153 mmol) ofenamine 2-3. After approximately 10 minutes a solid began to precipitateand heating was continued for an additional 10-15 minutes. During thistime the precipitate began to turn light brown and the heating wasdiscontinued. The mixture was cooled to ambient temperature and dilutedwith ether. The solid was collected by filtration and washed with etheraffording 2-4 as a light tan solid. The reaction was repeated withadditional enamine 2-3 until all enamine prepared in the previous stepwas consumed. This afforded 122 g (46% yield) of 2-4. M.W. 149.15; MS[M+1]⁺ 150; ¹H NMR (CDCl₃).

[0083] Compound 2-5

[0084] To a 500 mL, round bottom flask was charged 40 g (268 mmol) ofquinoline 2-4, 125 mL of acetonitrile and 125 mL (1340 mmol, 5 eq.) ofphosphorus oxychloride. The mixture was heated at 110° C. for 30minutes. The mixture was cooled to ambient temperature and poured ontoice and carefully neutralized to pH 5 with 6N sodium hydroxide. Themixture was filtered and the filtrate extracted 3× with ethyl acetate.The combined organic phases were washed with brine and dried overmagnesium sulfate. The solvent was removed in vacuo and the solidobtained combined with the initial precipitate. The precipitate waswashed with 1:1 hexane/ether and dried in vacuo affording 41 g (91%yield) of 2-5 as a light tan solid. M.W. 167.6; TLC 1:1 ethylacetate/hexane Rf=0.1; MS [M+1]⁺ 168; ¹H NMR (CDCl₃).

[0085] Compound 2-6

[0086] To a 1 L, round bottom flask was charged 41 g (247 mmol) of 2-5and 500 mL of 50% aqueous methanol. The solution was cooled in anice-bath and 15 mL (296 mmol, 1.2 eq.) of bromine in 30 mL of 50%aqueous methanol was added dropwise gradually affording a precipitate.Upon completion of the addition, the mixture was stirred for 30 minutes.The slurry was filtered and the filter cake slurried with water andcarefully neutralized with saturated sodium bicarbonate. The precipitatewas filtered, washed with water and dried in vacuo affording 60 g (98%yield) of 2-6 as a light yellow powder. M.W. 246.5; TLC 1:1 ethylacetate/hexane Rf=0.1; MS [M+1]⁺ 246, 248; ¹H NMR (CDCl₃).

Example 3 Synthesis of Intermediate for Structure (IV)

[0087]

[0088] Compound 3-2

[0089] Under nitrogen atmosphere, ethyl formate (7.38 g, 99.6 mmol) inanhydrous THF (100 mL) is added dropwise to a stirred mixture of NaH(1.75 g, 72.9 mmol) and Compound 3-1 (37.5 mmol) in THF (100 mL). Themixture is stirred over night. Additional portions of NaH and HCO₂Et (2equiv each) are added, and the mixture is refluxed for 30 min and thenstirred at room temperature overnight. After solvent evaporation, theresidue in ice cold water (100 mL) is adjusted to pH 6 with cold 6 N HCland is extracted with CHCl₃ (3×100 mL). The extract is washed with water(100 mL), dried (Na₂SO₄), and evaporated. The residue is triturated withhexane, which is decanted. Column chromatography of the residue onsilica gel (using CHCl₃ as eluant) gives compound 3-2.

[0090] Compound 3-3

[0091] A solution of compound 3-2 (5.31 mmol), methyl glycinatehydrochloride (1.00 g, 7.97 mmol), and sodium acetate (0.654 g, 7.97mmol) in MeOH (40 mL) and H₂O (10 mL) is stirred at room temperature for48 hr. The mixture is extracted with CHCl₃ (2×25 mL), and the organicextract is washed with water (20 mL), dried (Na₂SO₄), and evaporated.The residue (4.5 mmol) in dry CH₂Cl₂ (25 mL) is cooled to 0° C. andtreated with 1,5-diazabicyclo(4.3.0)non-5-ene (DBN, 1.12 g, 9.04 mmol)followed by ethyl chloroformate (0.735 g, 6.78 mmol). Afterrefrigeration for 24 h, 0.2 mL of DBN and 0.1 mL of ClCO₂Et are added toconsume the small quantity of remaining starting material. An additionalequivalent of DBN (0.6 g) is added, and the mixture is refrigerated for20 h. Solvent is evaporated and the gummy residue is chromatographed ona silica gel column (CHCl₃ eluant) to give compound 3-3.

[0092] Compound 3-4

[0093] HCl gas is bubbled into a solution of compound 3-3 andacetonitrile in dioxane at room temperature. The reaction is monitoredby TLC until all starting material is consumed. 10% aqueous ammoniumhydroxide is added until the mixture is basic, followed by extractionwith ethyl acetate. The organic layer is washed with water, dried overMgSO₄ and then evaporated to give a brown solid. The solid is dissolvedin POCl₃ and is heated at 100° C. for 2 hrs. The excess POCl₃ isevaporated in vacuo and the residue is neutralized with 2N NaOH.Extraction with ethyl acetate followed by drying over MgSO₄ andevaporation gives a residue which is purified by flash chromatography onsilica gel (Hexane/EtOAc, 4:1) to give compound 3-4.

Example 4 Synthesis of Intermediate for Structure (V)

[0094]

[0095] Compound 4-2

[0096] Under nitrogen atmosphere, ethyl formate (7.38 g, 99.6 mmol) inanhydrous THF (100 mL) is added dropwise to a stirred mixture of NaH(1.75 g, 72.9 mmol) and Compound 4-1 (37.5 mmol) in THF (100 mL). Themixture is stirred over night. Additional portions of NaH and HCO₂Et (2equiv each) are added, and the mixture is refluxed for 30 min and thenstirred at room temperature overnight. After solvent evaporation, theresidue in ice cold water (100 mL) is adjusted to pH 6 with cold 6 N HCland is extracted with CHCl₃ (3×100 mL). The extract is washed with water(100 mL), dried (Na₂SO₄), and evaporated. The residue is triturated withhexane, which is decanted. Column chromatography of the residue onsilica gel (using CHCl₃ as eluant) gives compound 4-2.

[0097] Compound 4-3

[0098] A solution of compound 4-2 (5.31 mmol), methyl glycinatehydrochloride (1.00 g, 7.97 mmol), and sodium acetate (0.654 g, 7.97mmol) in MeOH (40 mL) and H₂O (10 mL) is stirred at room temperature for48 hr. The mixture is extracted with CHCl₃ (2×25 mL), and the organicextract is washed with water (20 mL), dried (Na₂SO₄), and evaporated.The residue (4.5 mmol) in dry CH₂Cl₂ (25 mL) is cooled to 0° C. andtreated with 1,5-diazabicyclo(4.3.0)non-5-ene (DBN, 1.12 g, 9.04 mmol)followed by ethyl chloroformate (0.735 g, 6.78 mmol). Afterrefrigeration for 24 h, 0.2 mL of DBN and 0.1 mL of ClCO₂Et are added toconsume the small quantity of remaining starting material. An additionalequivalent of DBN (0.6 g) is added, and the mixture is refrigerated for20 h. Solvent is evaporated and the gummy residue is chromatographed ona silica gel column (CHCl₃ as eluant) to give compound 4-3.

[0099] Compound 4-4

[0100] A solution of compound 4-3 (9.9 mmol), ethyl acetoacetate (9.9mmol) and p-toluenesulfonic acid monohydrate (0.01 mmol) in 10 mL ofxylene is refluxed for 2 hrs. Half of solvent is removed by slowdistillation over 1 hour. The solution is allowed to cool to roomtemperature and a solution of potassium t-butoxide (9.8 mmol) in 24 mLof ethanol is added. This mixture is heated to 80° C. for 2 hrs. Themixture is diluted with ethyl acetate and washed with saturated NaClsolution. The organic layer is dried with sodium sulfate andconcentrated in vacuo. The residue is triturated with ether. The solidobtained is treated with an aqueous solution of LiOH (18 mL, 1M) inmethanol and the mixture is heated at reflux for 18 hr. The solution ispoured into a solution of 1M HCl (18 mL). The solution is extracted withethyl acetate, washed with brine, dried with sodium sulfate andconcentrated in vacuo to give a solid which is heated in diphenyl etherat 230° C. for 1.5 hr. The solid 4-4 obtained after diluting with etheris dried in vacuo.

[0101] Compound 4-5

[0102] The solid 4-4 is heated at 100° C. in POCl₃ for 2 hrs then isallowed to cool to room temperature. The reaction mixture is poured intoice and neutralized with NaHCO₃. The solution is extracted with ethylacetate. The organic layer is washed with brine, dried with sodiumsulfate and concentrated in vacuo. Compound 4-5 is purified by flashchromatography on silica gel eluting with ethyl acetate-hexane (1:3).

Example 5 Alternative Synthesis of Intermediate for Structure (V)

[0103]

[0104] Compound 5-1

[0105] Substituted 3-aminopyridine (1 eq) is dissolved in pyridine and1.5 eq of acetic anhydride is added. The mixture is stirred at roomtemperature for 1 day. Solvents are evaporated, water is added and theproduct is extracted with ethyl acetate. The organic layers arecombined, washed with water and brine, dried with MgSO₄ andconcentrated. The residue is purified by liquid chromatography to give5-1.

[0106] Compound 5-2

[0107] A solution of sodium (1.7 g) and compound 5-1 (5 g) in anhydrousethanol is evaporated to dryness and the residue is heated under dryhydrogen at 200° C. The temperature is slowly raised to 320° C. andmaintained there for 15 minutes during which time the mixture darkensand a vigorous evolution of gas occurs. To the cooled mixture, water(100 mL) is added and the insoluble pale yellow residue filtered off,dried and sublimed at 150° C./0.5 mm to give 5-2.

[0108] Compound 5-3

[0109] The solid 5-2 is heated at 100° C. in POCl₃ for 2 hrs then isallowed to cool to room temperature. The reaction mixture is poured intoice and neutralized with NaHCO₃. The solution is extracted with ethylacetate. The organic layer is washed with brine, dried with sodiumsulfate and concentrated in vacuo. The residue is purified by flashchromatography on silica gel eluting with ethyl acetate-hexane (1:3).Like fractions are collected and the solvent is evaporated giving aresidue which is dissolved in acetic acid. Bromine (2.2 g) in aceticacid is added dropwise and the mixture set aside. The needles whichseparated are crystallized from glacial acetic acid and are dissolved inwater. The addition of 1 equivalent of N-sodium hydroxide gives compound5-3.

Example 6 General Synthesis of Compounds of Structure (I)

[0110] The intermediates synthesized in Examples 1 through 5 may be usedto make compounds of structure (I) according to the following generalprocedure:

[0111] Compound 6-2

[0112] Chloro heterocycle 6-1 (40 mmol) from Example 1 through 5 isdissolved in 80 mL of a mixture of water/methanol (1/1) and is cooled inan ice-bath. A bromine solution (1.2 mL of bromine in 10 mL H₂O/MeOH1/1) is added dropwise to the cooled mixture. After 10 minutes, thesolution is clearer and the LC/MS shows no chloro compound. The reactionmixture is concentrated, extracted with ethyl acetate (3×100 mL). Theorganic phases are combined, washed with water (2×50 mL), a brinesolution (1×50 mL) and dried with sodium thiosulfate. The product ispurified by liquid chromatography (ethyl acetate/hexane 1/1 Rf 0.7) togive 6-2.

[0113] Compound 6-3

[0114] To compound 6-2 (10 mmol) in 20 mL of ethanol is added 3 mL ofhydrazine and 300 mg of p-toluensulfonic acid. The mixture is refluxedovernight. Ethanol is evaporated and water added. The precipitate formedis filtered and concentrated in vacuo to give solid 6-3 (80% yield).

[0115] Compound 6-4

[0116] To compound 6-3 (0.012 mol) in 40 mL of dichloromethane at 0° C.is added Et₃N (1.81 mL, 0.013 mol) followed by R₆C(O)Cl (0.013 mol). Themixture is stirred at room temperature overnight. Saturated solution ofbicarbonate is added, and the organic layer is separated. The waterlayer is extracted several times with ethyl acetate. Organic layers arecombined, dried with MgSO₄, and concentrated in vacuo to give a tansolid. POCl₃ (50 mL) is added to the solid obtained and the mixture isrefluxed for 24 hrs. Excess POCl₃ is evaporated in vacuo. Ice is addedto the residue and the mixture stirred for 1 hr then neutralized withNa₂CO₃. The product is extracted with ethyl acetate, dried with MgSO₄and concentrated in vacuo to give 6-4.

[0117] Compound 6-5

[0118] To bromo compound 6-4 (24 mmol) in 120 mL of toluene is added43.2 mL of ethanol. To the mixture is added R₁B(OH)₂ (36 mmol, 1.5 eq.),followed by 39.6 mL of 2.0 M aqueous sodium carbonate solution, 24 mL ofsaturated barium hydroxide and 1.9 g (0.3 mmol) of tetrakistriphenylphosphine palladium. The mixture is heated at 90° C. for 16 hr.The mixture is cooled and the organic phase separated. The aqueous phaseis extracted 3× with ethyl acetate and the combined organic extractsdried over magnesium sulfate and the solvent removed in vacuo. The crudeproduct is purified by flash silica gel chromatography eluting with 9:1dichloromethane/methanol affording compound 6-5 (69% yield).

[0119] Compound 6-6

[0120] To compound 6-5 (0.3 mmol) in DMF (10 mL) is added, undernitrogen atmosphere, NaH (9 mg, 0.36 mmol, 95%) and the mixture isstirred at room temperature for 15 min then R₅-halide (0.36 mmol) isadded and the mixture stirred at room temperature overnight. DMF isremoved in vacuo and the residue is dissolved in ethyl acetate andneutralized with 4 M HCl. The organic layer is dried with MgSO₄ andconcentrated in vacuo. The residue obtained is purified by preparativeTLC eluting with ethyl acetate-hexane (1:1) to give product 6-6 (i.e.,compound of Structure (I)).

Example 7 Synthesis of Representatvie Compounds of Structure (I)

[0121]

[0122] Compound 7-2

[0123] In a 5 L 3-neck flask equipped with a condenser and mechanicalstirrer under a nitrogen atmosphere was charged 600 g (3239 mmol, 1.5eq.) of potassium phthalimide followed by 1000 mL of anhydrous DMF. Thestirring was started and 480 g (2148 mmol) of 2, 2′,4′-trichloroacetophenone 7-1 in 600 mL of anhydrous DMF was chargeddrop-wise over 20 minutes. The reaction mixture became warm uponaddition. The mixture was stirred for 16 hours. The reaction wastriturated with 400 mL of ether and filtered over a pad of celite. Thefiltrate was poured into 3 L of water, which became warm and was cooledwith ice. The yellow precipitate was collected by filtration and washedwith water. The solid was air dried and then charged to a 5 L 3-neckflask equipped with a mechanical stirrer and a Dean-Stark trap. Theslurry was heated to reflux until no additional water was collected. Theslurry was filtered and washed with cold toluene. The light yellow solidwas dried in vacuo at 40° C. overnight affording 325 g (46% yield) of7-2. M.W. 334.16; TLC 1:5 ethyl acetate/hexane, R_(f)=0.3; GC t_(R)=8.25min.; MS [M+1]⁺ 334.

[0124] Compound 7-3

[0125] In a 2 L 3-neck flask equipped with a distillation head andmechanical stirrer under a nitrogen atmosphere was charged 220 g (650mmol) of 7-2 and 500 mL (3760 mmol, 5.6 eq.) of dimethylformamidedimethyl acetal. The mixture was heated to reflux and the methanolcollected by distillation. After 2 hours, most of the residual DMFDMAwas removed in vacuo affording a precipitate. The mixture was furthertriturated with ether. The solid was collected by filtration and washedwith ether. The product was dried in vacuo at 40° C. overnight affording205 g (81% yield) of 7-3. M.W. 389.24. TLC=1:1 Ethyl acetate/hexane,R_(f)=0.25; GC t_(R)=4.77 min.; MS [M+1]⁺ 389.

[0126] Compound 7-4

[0127] In a 5L 3-neck flask equipped with a condenser and mechanicalstirrer under a nitrogen atmosphere was charged 2000 mL of ethanol, 200mL of water, and 195 g (500 mmol) of 7-3. Stirring was started and 113 g(1000 mmol, 2.0 eq.) of hydrazine monohydrobromide added portion-wiseover 5 minutes. The slurry was heated to reflux for 5 hours. Thereaction mixture was cooled and 6.9 g (216 mmol, 1.0 eq.) of anhydroushydrazine was added. The reaction mixture was heated to reflux for 2hours. The mixture was cooled and filtered over celite and theprecipitate was washed with ethyl acetate. The filtrate was concentratedin vacuo affording 98 g (86% yield) of 7-4 as a brown foam. M.W. 228.08.TLC 1:1 ethyl acetate/hexane, R_(f)=0.2; GC t_(R)=6.79 min.; MS [M+1]⁺228.

[0128] Compound 7-5

[0129] In a 2 L round-bottom flask equipped with a condenser, Dean-Starktrap and stir bar was charged 117 g (516.0 mmol) of 7-4, 1200 mL oftoluene, 63.8 g (490 mmol, 0.95 eq.) of ethyl acetoacetate.Approximately 980 mg (0.5 mmol, 0.01 eq) of p-toluenesulfonic acid wasadded and agitation was started. The mixture was refluxed for 6 hrremoving approximately 7 mL of water. The mixture was cooled and thetoluene removed in vacuo affording 162 g (98% yield) of a yellow oil. 70g of the yellow oil was dissolved in 150 mL of diphenyl ether and thesolution was poured into diphenyl ether (150 mL) preheated to 250° C.The reaction mixture was heated at 250° C. for 30 minutes. The heat wasremoved and the mixture was allowed to cool to 25° C. The mixture wasthen chilled with an ice bath and poured into 800 mL of a 10:1hexane/ether mixture. The dark tan solid was filtered and washed withhexane. The solid was dried in vacuo at 40° C. affording 48.0 g of 7-5.M.W. 294.14.; MS [M+1]⁺ 294.

[0130] Compound 7-6

[0131] In a 250 mL round bottom flask equipped with a condenser and stirbar was charged 100 mL of anhydrous acetonitrile, 22 g (74.8 mmol) of7-5 and 57.0 g (374 mmol, 5.0 eq.) of phosphorus oxychloride. Themixture was refluxed for 4 hr and the solvent was removed in vacuo. Thedark oil was poured onto 400 g of crushed ice and neutralized with 4Npotassium hydroxide solution. The precipitate was filtered and washedwith water. The filtrate was extracted 3 times with ethyl acetate. Thecombined organic phases were washed with brine and dried over sodiumsulfate. The extracted material was combined with the precipitate anddried in vacuo affording 16.1 g (69% yield) of tan solid 7-6. TLC 1:1ethyl acetate/hexane Rf=0.6; M.W. 312.59; MS [M+1]⁺ 312.

[0132] Compound 7-7

[0133] To compound 7-6 (3 g) in 20 mL of ethanol was added 3 mL ofhydrazine and 300 mg of p-toluensulfonic acid. The mixture was refluxedovernight. Ethanol was evaporated and water was added. The precipitatewhich formed was filtered and dried to give 2.5 g of solid 7-7. MS[M+1]⁺ 309.

[0134] Compound 7-8

[0135] To compound 7-7 (3 g, 0.012 mol) in 40 mL of dichloromethane wasadded at ice bath temperature Et₃N (1.81 mL, 0.013 mol) followed byacetyl chloride (0.96 mL, 0.013 mol). The mixture was stirred at roomtemperature overnight. Saturated solution of bicarbonate was added, andthe organic layer was separated. The water layer was extracted severaltimes with ethyl acetate. Organic layers were combined, dried withMgSO₄, and concentrated in vacuo to give a tan solid. POCl₃ (50 mL) wasadded to the solid obtained and the mixture was refluxed for 24 hrs.Excess POCl₃ was evaporated in vacuo. Ice was added to the residue andthe mixture was stirred for 1 hr then neutralized with Na₂CO₃. Theproduct was extracted with ethyl acetate, dried with MgSO₄ andconcentrated in vacuo to give ˜3 g of 7-8 which was used as is in thenext step. MS [M+1]⁺ 332.

[0136] Compound 7-9

[0137] To compound 7-8 (100 mg, 0.3 mmol) in DMF (10 mL) was added,under nitrogen atmosphere, NaH (9 mg, 0.36 mmol, 95%) and the mixturewas stirred at room temperature for 15 min then 4-bromoheptane (0.36mmol) was added and the mixture was stirred at room temperatureovernight. DMF was removed in vacuo and the residue was dissolved inethyl acetate and neutralized with 4 M HCl to pH neutral. The organiclayer was dried with MgSO₄ and concentrated in vacuo. The residueobtained was purified by preparative TLC eluting with ethylacetate-hexane (1:1) to give 25 mg of 7-9. The material was furtherpurified by preparatory HPLC. MS [M+1]⁺ 431.

[0138] Compound 7-10

[0139] Substitution of 4-bromoheptane with 3-bromopentane afforded the3-pentyl alkylated product (7-10) which was purified by preparatoryHPLC. MS [M+1]⁺ 406.

Example 8 Alternative Synthesis of Representative Compound of Structure(I)

[0140]

[0141] In an alternative embodiment, rather than addition of the R₁group during initial synthesis steps, the R₁ group may be added at theend of the synthesis according to the following representativeprodecure.

[0142] Compound 8-2

[0143] To compound 8-1 (500 mg, 1.8 mmol) in DMF (20 mL) was added,under nitrogen atmosphere, NaH (54 mg, 2.2 mmol, 95%) and the mixturewas stirred at room temperature for 15 min then 4-bromoheptane (2.2mmol) was added and the mixture was stirred at room temperatureovernight. DMF was removed in vacuo and the residue was dissolved inethyl acetate and neutralized with 4 M HCl to pH neutral. The organiclayer was dried with MgSO₄ and concentrated in vacuo. The residueobtained was purified by preparative TLC eluting with ethylacetate-hexane (1:1) to give 125 mg of 8.2

[0144] Compound 8-3

[0145] To a mixture of 8-2 (100 mg, 8.16 mmol), 0.4 mL of 2M sodiumcarbonate, ethanol (0.6 mL) and toluene (2 mL) was added under nitrogenatmosphere Pd(Ph3)4 (5% mol). The mixture was heated at 90° C. overnight. The mixture was concentrated in vacuo and ethyl acetate and waterwere added. The organic layer was separated, dried over MgSO₄ andconcentrated in vacuo. The residue obtained was purified by preparativeTLC eluting with ethyl acetate-hexane (1:1) to yield 16 mg of compound8-3.

Example 9 Representative Compounds Having CRF Receptor Binding Activity

[0146] The compounds of this invention may be evaluated for bindingactivity to the CRF receptor by a standard radioligand binding assay asgenerally described by DeSouza et al. (J. Neurosci. 7:88-100, 1987). Byutilizing various radiolabeled CRF ligands, the assay may be used toevaluate the binding activity of the compounds of the present inventionwith any CRF receptor subtype. Briefly, the binding assay involves thedisplacement of a radiolabeled CRF ligand from the CRF receptor.

[0147] More specifically, the binding assay is performed in 1.5 mlEppendorf tubes using approximately 1×10⁶ cells per tube stablytransfected with human CRF receptors. Each tube receives about 0.1 ml ofassay buffer (e.g., Dulbecco's phosphate buffered saline, 10 mMmagnesium chloride, 20 μM bacitracin) with or without unlabeledsauvagine, urotensin I or CRF (final concentration, 1 μM) to determinenonspecific binding, 0.1 ml of [¹²⁵I] tyrosine-ovine CRF (finalconcentration ˜200 pM or approximately the K_(D) as determined byScatchard analysis) and 0.1 ml of a membrane suspension of cellscontaining the CRF receptor. The mixture is incubated for 2 hours at 22°C. followed by the separation of the bound and free radioligand bycentrifugation. Following two washes of the pellets, the tubes are cutjust above the pellet and monitored in a gamma counter for radioactivityat approximately 80% efficiency. All radioligand binding data may beanalyzed using the non-linear least-square curve-fitting program LIGANDof Munson and Rodbard (Anal. Biochem. 107:220, 1990).

Example 10 CRF-Stimulated Adenylate Cyclase Activity

[0148] The compounds of the present invention may also be evaluated byvarious functional testing. For example, the compounds of the presentinvention may be screened for CRF-stimulated adenylate cyclase activity.An assay for the determination of CRF-stimulated adenylate cyclaseactivity may be performed as generally described by Battaglia et al.(Synapse 1:572, 1987), with modifications to adapt the assay to wholecell preparations.

[0149] More specifically, the standard assay mixture may contain thefollowing in a final volume of 0.5 ml: 2 mM L-glutamine, 20 mM HEPES,and 1 mM IMBX in DMEM buffer. In stimulation studies, whole cells withthe transfected CRF receptors are plated in 24-well plates and incubatedfor 1 h at 37° C. with various concentrations of CRF-related andunrelated peptides in order to establish the pharmacological rank-orderprofile of the particular receptor subtype. Following the incubation,the media is aspirated, the wells rinsed once gently with fresh media,and the media aspirated. To determine the amount of intracellular cAMP,300 μl of a solution of 95% ethanol and 20 mM aqueous hydrochloric acidis added to each well and the resulting suspensions are incubated at−20° C. for 16 to 18 hours. The solution is removed into 1.5 mlEppendorf tubes and the wells washed with an additional 200 μl ofethanol/aqueous hydrochloric acid and pooled with the first fraction.The samples are lyophilized and then resuspended with 500 μl sodiumacetate buffer. The measurement of cAMP in the samples is performedusing a single antibody kit from Biomedical Technologies Inc.(Stoughton, Mass.). For the functional assessment of the compounds, asingle concentration of CRF or related peptides causing 80% stimulationof cAMP production is incubated along with various concentrations ofcompeting compounds (10⁻¹² to 10⁻⁶ M).

[0150] It will be appreciated that, although specific embodiments of theinvention have been described herein for purposes of illustration,various modifications may be made without departing from the spirit andscope of the invention. Accordingly, the invention is not limited exceptas by the appended claims.

1. A compound having the following structure:

or a stereoisomer, prodrug or pharmaceutically acceptable salt thereof,wherein: X is nitrogen or CR₃; Y is nitrogen or CR_(4;) R₁ is alkyl,substituted alkyl, —NR₇R₈, aryl, substituted aryl, heteroaryl orsubstituted heteroaryl; R₂ is hydrogen, alkyl, alkoxy, thioalkyl orhaloalkyl; R₃ is hydrogen, alkyl, halo or haloalkyl; R₄ is hydrogen,halogen, —NR₇R₈, alkyl, alkoxy, thioalkyl or haloalkyl; R₅ is hydrogen,alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl orsubstituted heteroaryl; R₆ is hydrogen, alkyl, substituted alkyl,—NR₇R₈, —OR₉, —SR₉, aryl, substituted aryl, heteroaryl or substitutedheteroaryl; R₇ and R₈ are the same or different and independentlyhydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroarylor substituted heteroaryl; and R₉ is alkyl, substituted alkyl, aryl,substituted aryl, heteroaryl or substituted heteroaryl.
 2. The compoundof claim 1 wherein X is CR₃.
 3. The compound of claim 1 wherein X isnitrogen.
 4. The compound of claim 1 wherein Y is CR₄.
 5. The compoundof claim 1 wherein Y is nitrogen.
 6. The compound of claim 1 wherein R₁is substituted aryl or substituted heteroaryl.
 7. The compound of claim1 wherein R₅ is alkyl, substituted alkyl, aryl or substituted aryl. 8.The compound of claim 6 wherein R₅ is alkyl, substituted alkyl, aryl orsubstituted aryl.
 9. The compound of claim 7 wherein R₁ is —NR₇R₈. 10.The compound of claim 1 wherein both X and Y are nitrogen.
 11. Thecompound of claim 1 wherein X is CR₃ and Y is nitrogen.
 12. The compoundof claim 1 wherein X is nitrogen and Y is CR₄.
 13. The compound of claim1 wherein X is CR₃ and Y is CR₄.
 14. A composition comprising a compoundof claim 1 in combination with a pharmaceutically acceptable carrier ordiluent.
 15. A method for treating a disorder manifesting hypersecretionof CRF in a warm-blooded animal, comprising administering to the animalan effective amount of the pharmaceutical composition of claim
 14. 16.The method of claim 15 wherein the disorder is stroke.
 17. The method ofclaim 15 wherein the disorder is depression.
 18. The method of claim 15wherein the disorder is anxiety.
 19. The method of claim 15 wherein thedisorder is irritable bowel syndrome.